新型长寿命低温处理透气砖的研制及应用

本文研制了一种新型低温处理透气砖,该透气砖在传统的刚玉.尖晶石体系中引入了2%～4%的单斜ZrO2,明显改善了材料的高温强度和抗侵蚀性能,尤其是材料的抗热震性明显优于烧成刚玉.尖晶石透气砖.该透气砖在生产过程中省略了高温生成工艺,能耗低于烧成透气砖,节约了能源,降低了生产成本.低温处理透气砖在60 t以下中小钢包上,使用次数可以达到128次,优于烧成刚玉-尖晶石质透气砖,在90 t以上大型钢包精炼上使用效果略优于刚玉-尖晶石透气砖.     

钢包底吹用刚玉-尖晶石透气砖

对钢包底吹用经振动成型并烧成后的刚玉-尖晶石透气砖的组成改变的研究结果进行了研究,引入富铝尖晶石[m（Al2O3）：m（MgO）=85：15]的刚玉-尖晶石透气砖的抗渣性比引入接近化学计量比的镁铝尖晶石的透气砖的抗渣性提高了2．5倍。该高级刚玉-尖晶石透气砖在乌克兰4家冶金公司使用,使用结果表明,透气砖的使用寿命显著提高。     

精炼钢包用透气砖的研究进展与发展方向

总结了精炼钢包用透气砖的损毁原因和现用刚玉-尖晶石透气砖在改善抗热震性方面的研究新进展;介绍了非氧化物结合刚玉质透气砖的研究结果和在精炼钢包上的使用情况,提出了透气砖的研究和发展方向。     

ρ-Al2O3结合铝镁铬质透气砖的研制与应用

着对钢水洁净度要求的提高 ,钢包精炼得到了普及 ,钢包底吹氩气透气砖被日益广泛地应用于精炼工艺上。吹氩具有均化钢水 ,使夹杂物上浮 ,提高钢水质量的作用 ,透气砖作为钢包底吹供气元件起着非常重要的作用。本研究研制出了具有合理狭缝结构的烧成无水泥铝镁铬质透气砖 ,并在 2 5t转炉钢包和 45tLF精炼钢包上进行了批量使用 ,证明其使用效果良好。1　设计思路本实验以铝镁尖晶石体系为出发点进行设计。由于使用铝酸钙水泥为结合剂会导致高温下生成尖晶石和六铝酸钙 ,产生的体积效应使透气砖的尺寸难于控制 ,烧成废品率高 ,使用中也会出现…     

用后钢包透气砖显微结构分析

对60 t LF VD精炼钢包用刚玉-尖晶石透气砖和45 t LF精炼钢包用铬刚玉-尖晶石透气砖用后残砖进行了显微结构分析。结果表明:LF精炼工艺用透气砖狭缝及裂纹有明显的渣侵蚀和渗透,LF VD精炼工艺用透气砖狭缝和裂纹有钢液渗透。在周期性操作过程中,狭缝口部的扩大和热震造成的裂纹会使钢液或渣液的渗透侵蚀作用加剧并导致剥落现象的发生。透气砖狭缝堵塞直接影响吹通率和使用寿命,所以,要优化狭缝尺寸,提高材料的抗热震性。     

钢包用刚玉-尖晶石砖

以电熔白刚玉、电熔尖晶石、氧化铝微粉为主要原料,经高温烧成,制成高纯刚玉－尖晶石钢包衬砖。制品性能优良,耐渣蚀、抗渗透。在钢包上使用取得良好效果     

一种长寿命透气砖的研制与应用

以板状刚玉、电熔白刚玉、α-Al2O3微粉(双峰型)、Secar 71水泥和烧结尖晶石为主要原料,通过优化骨料的粒度级配并添加一种具有减水和助烧作用的添加剂,成功研制出一种致密、高强的新型透气砖。在精炼钢包上进行的现场应用试验表明,新型透气砖具有抗热震断裂能力强,抗渣侵蚀性能好等特点,使用寿命远大于传统透气砖。     

天然气反吹条件下刚玉-尖晶石质钢包透气砖损毁分析

为了探讨天然气反吹条件下刚玉-尖晶石质钢包透气砖不能正常吹通的原因,采用XRD、SEM及EDAX对用后透气砖的物相组成和显微结构进行分析,并结合热力学计算分析天然气的碳化反应以及天然气和透气砖组分之间的反应。结果表明:采用天然气反吹时CH4分解反应造成的碳沉积和扩散,CH4和尖晶石反应引起尖晶石中MgO还原-氧化循环造成的强度降低,以及由此引起的透气砖不同部位膨胀系数的不匹配导致透气砖在精炼时头部断裂,而头部断裂导致的狭缝错位是刚玉-尖晶石质透气砖不能正常吹通的直接原因。     

钢包用刚玉-尖晶石透气砖的研制与应用

研究了基质中MgO含量对以电熔刚玉、尖晶石为主要原料制成的刚玉 -尖晶石透气砖 (砖芯 )性能的影响 ,并比较了刚玉 -尖晶石砖与传统铬刚玉砖的性能。结果表明 :刚玉 -尖晶石砖热震稳定性优于铬刚玉砖 ,但其体积稳定性不如铬刚玉砖 ,生产中不易控制 ;工业试验表明 ,刚玉 -尖晶石透气砖 (砖芯和座砖 )优于传统铬刚玉透气砖。     

弥散型铬刚玉质整体透气砖的应用

安钢多年来精炼钢包使用的均为小型刚玉质分体透气砖,钢水易通过砖缝侵入透气砖周围加快对透气砖的侵蚀,与钢包寿命不能同步。目前,在25ｔ电炉钢包上试用了弥散型铬刚玉质整体透气砖。该产品具有较高的耐磨性、耐冲刷性及耐钢水、渣侵蚀性,寿命已达55次,解决了与钢包寿命不同步的问题。1　用后砖的矿物组成挂渣层厚约0～2.5ｍｍ,主矿相为板柱状钙铝黄长石和硅酸盐胶结相以及少量复合尖晶石。蚀变层约2.5ｍｍ,主要矿相为复合尖晶石及少量钙铝黄长石、铝酸钙和氧化铬。渗透层结构致密,硅酸盐胶结相增多,氧化铬周围反应生成了复合尖晶石,矾土颗…     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。